commit 5b630ff82b35b713941db094bef7a7beb6af66f1
author Robert Newson <rnewson@apache.org> Wed Dec 03 12:14:10 2014 +0000
committer Mike Wallace <mikewallace@apache.org> Fri Jun 05 17:20:15 2015 +0100
tree e53ec1ec0d1f17cf40bdab88692eb42e0b740433
parent 362b3fd490d00015ea13fe24b62b925c1acb6ea5

delay and splay replication starts

This is a cherry-pick of:

https://github.com/cloudant/couch_replicator/commit/d279150d959cfd46cbd77c5dd17f14d6dc3d0291

src/couch_replicator_manager.erl

diff --git a/src/couch_replicator_manager.erl b/src/couch_replicator_manager.erl
index 17c766e..eefa0cd 100644
--- a/src/couch_replicator_manager.erl
+++ b/src/couch_replicator_manager.erl
@@ -454,7 +454,14 @@
         true = ets:insert(?DOC_TO_REP, {{DbName, DocId}, RepId}),
         couch_log:notice("Attempting to start replication `~s` (document `~s`).",
             [pp_rep_id(RepId), DocId]),
-        Pid = spawn_link(?MODULE, start_replication, [Rep, 0]),
+        StartDelaySecs = erlang:max(0,
+            config:get_integer("replicator", "start_delay", 10)),
+        StartSplaySecs = erlang:max(1,
+            config:get_integer("replicator", "start_splay", 50)),
+        DelaySecs = StartDelaySecs + random:uniform(StartSplaySecs),
+        couch_log:notice("Delaying replication `~s` start by ~p seconds.",
+            [pp_rep_id(RepId), DelaySecs]),
+        Pid = spawn_link(?MODULE, start_replication, [Rep, DelaySecs]),
         State#state{rep_start_pids = [Pid | State#state.rep_start_pids]};
     #rep_state{rep = #rep{doc_id = DocId}} ->
         State;